This invention relates to an information processing apparatus, including but not limited to, a notebook PC (personal computer) and, more particularly, to an information processing apparatus of the type which has a plurality of peripheral devices for outputting audio signals, and provides an audio output by an audio amplifier and a speaker. More specifically, this invention relates to an information processing apparatus that is designed to implement a power-saving function for an audio amplifier in accordance with an unused state of each peripheral device for outputting an audio signal.
With the technological revolution, different types of PCS, such as desktop type, tower type and notebook type, have been developed and are commercially available in the marketplace. Of these PCS, a notebook PC has been designed and manufactured to have a smaller size and be of a lighter weight, thereby to improve its mobility/portability and adaptability for outdoor use.
One of the features of a notebook PC resides in that it may be driven by a battery provided internally to its system unit. This is because it has been designed on an assumption that a commercial power supply is not normally available under a mobile environment. In general, a battery used by a notebook PC is in the form of a xe2x80x9cbattery packxe2x80x9d, which comprises a plurality of rechargeable battery cells of Li-Ion, NiCd, NiMH or the like. While such a battery pack is said to be reusable through the process of charging, nevertheless it takes 2 to 3 hours to charge it up to its full capacity, even. though such a full capacity is durable for 2 to 3 hours at most, in terms of computer processing time. Accordingly, for the purpose of extending an operable duration of a battery, a variety of ideas for power-saving have been proposed in the past. Thus, a positive introduction of a power-saving function is generally regarded as another feature of a notebook PC.
Also, even for a desktop type PC driven by a commercial power supply, there has been an increased demand for power-saving from an ecological standpoint. In this respect, the Environmental Protection Agency in the U.S.A. in June 1993 has announced voluntary constraints, called xe2x80x9cEnergy Star Computer Programxe2x80x9d,and requested that power consumption of a computer during its standby state be less than a predetermined level (e.g., driving power of 30 W, or 30% of nominal power consumption, when a CPU is fully operating). Accordingly, respective computer makers have competitively developed and manufactured desktop PC products following this voluntary program.
A very basic point of power-saving designs for a variety of electric/electronic apparatuses, including PCS, is to stop power feeding to a device or circuit that is not currently in use. For example, U.S. Pat. No. 4,933,785 discloses a technique adapted for use in a hard disk drive (HDD) such that power feeding to its internal electric circuits is sequentially stopped in accordance with an operational status of the drive (i.e., the elapsed time from the last access to a disk), as set forth in claim 45 of the U.S. Pat. No. 4,933,785.
PCS are now incorporating a rapidly expanded multimedia function (i.e., the function for handling various data elements, which includes motion pictures, still pictures, sounds and characters, in addition to conventional computer data, on a computer system in a composite or integrated manner). This function has a variety of applications, ranging from execution of software recorded on a CD-ROM (compact disk) to communication/broadcasting fields such as a TV conference and a color facsimile. In connection with this, a certain type of peripheral device having audio signal outputs (e.g., a CD-ROM drive, a modem and an audio CODEC) has been installed onto a PC""s system unit as its standard or optional feature. Also, as a result of an attempt to define an industrial standard, there has appeared a ZV (Zoom Video) port that is compatible with a PC card slot. A ZV port compatible PC card implements a fast motion picture display by directly transferring data to/from a video controller, and it has inputs/outputs for video and audio signals respectively. In other words, an audio function is now regarded as an essential feature of a multimedia PC, and it may be accomplished by acoustically outputting an audio signal from each peripheral device through an audio amplifier, a technique which is well known in the art.
With regard to the power-saving designs, as described above, the very basic point of the power-saving designs is to stop power feeding to a circuit module that is currently in an unused state. However, no substantial attempt has been ever made in the field of PCS to provide a power-saving design for an audio amplifier. This is primarily because it has been difficult to precisely detect an unused state of an audio amplifier since a certain number of peripheral devices (e.g., a CD-ROM drive, an audio CODEC and a modem) are involved, each outputting an audio signal.
Many of the audio amplifiers for use in portable type equipment are configured to have power control pins (power-saving pins) that may be used for controlling an ON/OFF state in response to inputs applied to these pins. However, notwithstanding the provision of such pins, the respective audio amplifier has been normally maintained in an ON state, thereby to continually consume electric power at a certain level on a motherboard of a PC. While an audio amplifier consumes about 100 mW of electric power, this level of power consumption is not negligible for a battery-driven PC.
It is, therefore, an object of this invention to provide an improved information processing apparatus, which incorporates a power-saving design. It is another object of this invention to provide an improved information processing apparatus, which accomplishes power-saving in accordance with an Unused state of a peripheral device. It is yet another object of this invention to provide an improved information processing apparatus, which accomplishes power-saving of an audio amplifier in accordance with an activity of each peripheral device having an audio signal output.
This invention has been made in view of the stated problems and its first aspect resides in an information processing apparatus, including: one or more peripheral devices, each having an audio signal output and a mute signal output, the mute signal output indicating a mute state in which the peripheral device does not output an audio signal; an audio amplifier for receiving the audio signal from each of the one or more peripheral devices; a speaker for generating an audible output in accordance with an output of the audio amplifier; and an AND gate for receiving the mute signal from each of the one or more peripheral devices to perform a logical AND operation of the mute signals, the AND gate outputting a control signal for disabling the audio amplifier when all of the mute signals indicate the mute state.
The second aspect of this invention resides in an information processing apparatus, including: one or more peripheral devices, each having an audio signal output; an audio amplifier for receiving the audio signal from each of said one or more peripheral devices; a speaker for generating an audible output in accordance with an output of said audio amplifier; and power saving means for monitoring whether or not each of said one or more peripheral devices stays at a mute state in which the said peripheral device does not output the audio signal, and for switching said audio amplifier to a power-saving state only when all of said one or more peripheral devices stay at the mute state.
The third aspect of this invention resides in a power saving apparatus for an audio amplifier adapted for use in an information processing apparatus of the type, which has one or more peripheral devices each outputting an audio signal, and generates an audible output by said audio amplifier and a speaker, including structure for receiving a mute signal from each of the one or more peripheral devices, the mute signal indicating a mute state in which the peripheral device does not output an audio signal; and device for performing a logical AND operation of the received mute signals, and for outputting a control signal to disable the audio amplifier when all of the mute signals indicate the mute state.
The fourth aspect of this invention resides in a power saving apparatus for an audio amplifier adapted for use in an information processing apparatus of the type, which has one or more peripheral devices each outputting an audio signal, and generates an audible output by the audio amplifier and a speaker, including monitoring device for monitoring whether or not each of said one or more peripheral devices stays at a mute state in which the peripheral device does not output the audio signal; and power saving device for switching the audio amplifier to a power-saving state only when all of the one or more peripheral devices stay at the mute state.
In each aspect of this invention, the peripheral device for outputting an audio signal may include a modem, a CD-ROM drive, an audio controller, a ZV port compatible PCMCIA (Personal Computer Memory Card International Association) card slot, and the like. The modem card 27 enters into a non-mute state during the off-hook operation, which corresponds with the conversational state. Also, when the PCMCIA slot is used as a ZV port, there exists an audio signal output and, thus, the PCMCIA slot enters into a non-mute state.
Therefore, in accordance with an information processing apparatus and a power saving apparatus of this invention, it is determined whether or not each peripheral device for outputting an audio signal stays at the mute state, and the audio amplifier is disabled only when all of these peripheral devices stay at the mute state. In other words, it becomes possible to precisely detect an unused state of the audio amplifier, whereby its power consumption may be definitely reduced in such an unused state.
The foregoing and other objects, features and advantages of this invention will be apparent from the following detailed description of an embodiment of this invention, as illustrated in the accompanying drawings.